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Mesoginella turbinata (Sowerby, 1846) Diagnosis: Shell
small to medium, white or cream, not strongly narrowed anteriorly; spire
low; shoulder of body whorl smooth, or with few or many, weak to strong
axial ribs; aperture moderately narrow; lip thickened internally,
smooth, thickest centrally; external varix present, continuing as a callus
around base; weak siphonal notch present; posterior notch weak;
ventral callus thin; columella with four strong plaits occupying
slightly less than half the aperture, 4th plait more widely
spaced. Size: Adults 5-10 mm in length. Distribution: Australian
Museum Collection: Ballina, NSW, to south-western WA, including Comparison: Distinguished by the folds on the body whorl when present; also smooth inside of the outer lip. The outer lip varix continues as a callous around the base, diagonally across the ventral surface to the fourth columella plait, a feature also seen in M. olivella. (See Identification of beach specimens) Synonymy: Marginella
albina Gaskoin 1853; Marginella
pattisoni Cotton, 1944; Marginella
leia Cotton, 1944. Laseron named a subspecies M.
turbinata pusilla Laseron, 1948, describing it as small for the
species (6.5 mm) and broader than normal (Hewish
in Wilson, 1994). The range of specimens now
available shows this to fall well within the range of variation. Remarks: This species shows considerable variation in size and sculpture. The body whorl may be completely smooth, or with ribs that vary from a few near the varix to strong on all of the body whorl. It is common as a beach shell on Sydney outer beaches. Figs. 1a, 2a: Between Sydney Heads in 27 m (C.316422); this is the specimen figured by Laseron (1948, fig. 1) Figs. 1b, 2b: Twofold Bay, NSW, in 15 m (C.317006) |
